If directory indexing is not enabled, you can still check for the presence of the .git folder and you'll have to essentially brute force what you need using git fsck. DVCS-Pillage and DVCSRipper do this for you.

I do this by looking for files like .git/config.

Decent admins will give you 404 or 403 for .git/ but will return the contents of .git/config.

You can then run DVCS-Pillage/dvcs-ripper to pull down the files.

One thing that will sometimes happen is that you can download parts of the git repo but the tools mentioned above will fail to get the whole thing. you can just